In many of today's control systems, actuators are constantly operating in order to maintain a certain level of an environmental parameter in an operating area. For instance in a mine, fans are operating to ventilate the mine irrespective of if humans and/or working machines are present in a certain area of the mine or not. Other ventilation systems for mines are controlled manually, and ventilation is increased manually in areas where work is performed. In refrigerating chambers cooling elements are operating in response to a single thermometer, although the temperature can be correct in some areas of the chamber while to high in others.
EP 1068602 B1 discloses a control system in which actuators in a building are controlled in response to human physiological signals, wirelessly transmitted from a sensor device carried by a human to a common control device which controls the operation of the actuators. For instance, it is disclosed that the air-conditioning of the building can be controlled by the control device in response to sensor signals from sensor devices, which measure the temperature of the skin of humans carrying said sensor devices in said building. The effect of the air-conditioning is then controlled so as to optimize the skin temperature of humans in the building.